ET USER_AGENTS Suspicious User-Agent (App4)

Query · suricata

flow:to_server,established;
threshold:type limit, count 2, track by_src, seconds 300;
http.user_agent;
content:"App"; depth:3; fast_pattern;
pcre:"/^\d/R";
http.host;
content:!"liveupdate.symantecliveupdate.com";
Raw source ET USER_AGENTS Suspicious User-Agent (App4) · Suricata
Esc
Published by Emerging Threats Open ↗, licensed under BSD 3-Clause ↗. Line breaks added for readability; the rule is otherwise unchanged. 
alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET USER_AGENTS Suspicious User-Agent (App4)";
    flow:to_server,established;
    threshold:type limit, count 2, track by_src, seconds 300;
    http.user_agent;
    content:"App"; depth:3; fast_pattern;
    pcre:"/^\d/R";
    http.host;
    content:!"liveupdate.symantecliveupdate.com";
    classtype:trojan-activity;
    sid:2008073; rev:16;
    metadata:affected_product Any, attack_target Client_Endpoint, created_at 2010_07_30, deployment Perimeter, confidence High, signature_severity Major, tag User_Agent, updated_at 2020_08_17;
)

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